TODO: new plan to kill QueueCreator

Change-Id: I098307063f7645889a39dedafc4d3f862a3f798c

TODO

@@ -35,12 +35,27 @@ Offline list:
    where the lifetime of the background daemon will be the same as the
    user's login session.
 
--- support syncing from a storage type that doesn't support
-   QueueCreator by using local disk instead. writes go to both 1) that
-   storage target not supporting QueueCreator and 2) local disk before
-   being acknowledged. Then sync goes from local disk to wherever,
-   deleting from local disk when done as normal (except in that case,
-   the hardlink refcount would drop from 1 to 0, not 2 to 1)
+-- Get rid of QueueCreator entirely. Plan:
+     -- sync handler still has a source and dest (one pair) but
+        instead of calling CreateQueue on the source, it instead
+        has an index.Storage (configured via a RequiredObject
+        so it can be a kvfile, leveldb, mysql, postgres etc)
+     -- make all the index.Storage types be instantiable
+        from a jsonconfig Object, perhaps with constructors keyed
+        on a "type" field.
+     -- make sync handler support blobserver.Receiver (or StatReceiver)
+        like indexes, so it can receive blobs.  but all it needs to
+        do to acknowledge the ReceiveBlob is write and flush to its
+        index.Storage. the syncing is async by default. (otherwise callers
+        could just use "replica" if they wanted sync replication).
+        But maybe for ease of configuration switching, we could also
+        support a sync mode.  when it needs to replicate a blob,
+        it uses the source.
+     -- future option: sync mirror to an alternate path on ReceiveBlob
+        that can delete. e.g. you're uploading to s3 and google,
+        but don't want to upload to both at once, so you use the localdisk
+        as a buffer to spread out your upstream bandwidth.
+     -- end result: no more hardlinks or queue creator.
 
 -- website: remove the "Installation" heading for /cmd/*, since
    they're misleading and people should use "go run make.go" in the